Yeah, I'm back. Unbelievably, except for a brief post a month ago to say I was alive, I have now not posted for six weeks. But I'm back...

So the big big news, in an otherwise big news day, was yesterday's announcement by NASA engineers that Opportunity has found "strong evidence" that Meridiani Planum was wet. And not just damp; "Liquid water once flowed through these rocks. It changed their texture, and it changed their chemistry." To me this is not surprising, but it is amazing, on several levels.

First, if we go on to discover that Mars held (or indeed holds!) life, this will be seen as the first harbinger. That would be amazing. Unbelievably amazing, actually. But even if we don't discover such evidence, what's amazing also is our ability to detect and interpret this evidence. The Earth is roughly 5 billion years old. Homo Sapiens are roughly 150,000 years old, a mere blip. But only in the last twenty years or so have we had the technology to send robots to another planet which can probe for this kind of information, and transmit it back. That's amazing. And the geological knowledge that enables scientists to interpret this information, with confidence, is amazing as well.